Why stop at corporate? What about union and ABA money flooding the democrat party?
I didn't say that we should stop there. I said removing corporate money from politics would change business.
FWIW, among the top 140 reported direct donors since 1989 corporate giving totaled around $1.2 billion while unions only gave a little under $660 million. Professional organizations, of which ABA is but one only donated a little under $141 million. Interestingly, ActBlue is #1, but even including them, lobbying organizations/think tanks in the top 140 only gave a little over $151 million. Donors that I could not identify offhand as being one of the previous groups accounted for almost $89 million in giving.
Edited to add: Also, donations from professional organizations like ABA, AICPA, AMA, and so on have actually not been heavily biased towards Democrats. In fact, Republicans got more donations from that group than Dems did, about $74.5 million for Republicans and $63.5 million for Democrats. Unions, on the other hand, definitely send most of their money to Democrats. No wonder, though, given the unending demonization of unions by the Republican Party and most of its candidates.
Edited again to note: This doesn't include money spent on indirect ads or issue ads or anything else that doesn't get reported to the FEC, and I'm only using the top 140 donors.